SSQ 250/5K Equivalent & Substitute Parts

Part Overview

The SSQ 250/5K is a 250 mA surface mount board mount fuse rated for 125 V AC/DC operation, manufactured by Bel Fuse Inc. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The fuse features fast blow response characteristics and is housed in a 2-SMD square end block package suitable for automated assembly processes.

Substiute Parts

SSQ 250/5K

Bel Fuse Inc.In Stock: 757SSQ 250/5K Datasheet

Current PartRFQ

0679L0250-05

Bel Fuse Inc.In Stock: 1125410679L0250-05 Datasheet

DirectRFQ

0451.250MRSN

Littelfuse Inc.In Stock: 8850451.250MRSN Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SSQ 250/5K is determined by strict equivalence across the following parameters:

• Current rating: 250 mA (exact match required)
• Voltage ratings: 125 V AC and 125 V DC (exact match required)
• Response time: Fast Blow (exact match required)
• Mounting type: Surface Mount (exact match required)
• Package type: 2-SMD, Square End Block (exact match required)
• Operating temperature range: -55°C to 125°C (exact match required)
• RoHS compliance: ROHS3 Compliant (exact match required)

Two substitute parts meet these criteria:

1. 0679L0250-05 (Bel Fuse Inc.) – Direct manufacturer equivalent with active product status
2. 0451.250MRSN (Littelfuse Inc.) – Similar part from alternative manufacturer with active product status

Parameter Comparison

Engineering Selection Recommendations

0679L0250-05 is the primary substitute for SSQ 250/5K applications. This part is manufactured by the same supplier (Bel Fuse Inc.), maintains identical electrical specifications, and carries active product status with significantly higher inventory availability (112,449 units). The part holds AEC-Q200 automotive qualification and cURus certification, providing enhanced reliability documentation for critical applications.

0451.250MRSN serves as an alternative substitute from Littelfuse Inc. (NANO²® 451 series). This part meets all core electrical and mechanical requirements with active product status. The melting I²t value (0.0158) is slightly lower than the original specification (0.02), and DC voltage rating is not explicitly specified in available documentation. This part carries CSA and UR certifications and is suitable for applications where multi-source qualification is required.

Both substitute parts are ROHS3 compliant, operate across the full -55°C to 125°C temperature range, and are available in tape and reel packaging for automated assembly.

Frequently Asked Questions (FAQ)

Q: Can SSQ 250/5K be directly replaced with 0679L0250-05?

A: Yes. Both parts share identical current rating (250 mA), voltage ratings (125 V AC/DC), response time (Fast Blow), package type (2-SMD square end block), and operating temperature range (-55°C to 125°C). The primary difference is product status: SSQ 250/5K is obsolete while 0679L0250-05 is active with higher inventory availability.

Q: What is the difference between 0679L0250-05 and 0451.250MRSN?

A: Both parts meet the core substitution criteria for SSQ 250/5K. Key differences include manufacturer (Bel Fuse vs. Littelfuse), melting I²t specification (0.02 vs. 0.0158), DC cold resistance (0.61 vs. 0.5765 Ohms), and certification profiles (AEC-Q200/cURus vs. CSA/UR). The 0451.250MRSN does not explicitly specify DC voltage rating in available documentation.

Q: Are there packaging differences between these parts?

A: All three parts use 2-SMD square end block packages suitable for surface mount assembly. The primary packaging difference is availability: SSQ 250/5K and 0451.250MRSN are available in tape and reel format, while 0679L0250-05 is also supplied in tape and reel with significantly higher stock levels.

Q: Which substitute should be selected for new designs?

A: Selection depends on supply chain and certification requirements. For Bel Fuse continuity and AEC-Q200 qualification, use 0679L0250-05. For multi-source qualification or Littelfuse preference, use 0451.250MRSN. Both parts are electrically and mechanically compatible with SSQ 250/5K applications.

Q: Are all three parts RoHS compliant?

A: Yes. SSQ 250/5K, 0679L0250-05, and 0451.250MRSN are all ROHS3 compliant and REACH unaffected.